OAKLAND, Calif. (AP) — Demonstrators opposed to the election of Donald Trump smashed windows and set garbage bins on fire in downtown Oakland, California early Wednesday, as protesters swarmed streets across the country in response to the election. The protests elsewhere were generally peaceful.

In Oregon, dozens of people blocked traffic in downtown Portland and forced a delay for trains on two light rail lines. Media reports said the crowd grew to about 300 people, including some who sat in the middle of the road to block traffic. The crowd of anti-Trump protesters burned American flags and chanted “That’s not my president.”

In Pennsylvania, hundreds of University of Pittsburgh students marched through the streets, with some in the crowd calling for unity. The student-run campus newspaper, the Pitt News, tweeted about an event later Wednesday titled “Emergency Meeting: Let’s Unite to Stop President Trump.”

Madeline Lopes, left, and Cassidy Irwin, both of Oakland, march with other protesters in downtown Oakland, Calif., early Wednesday, Nov. 9, 2016. President-elect Donald Trump’s victory set off multiple protests. (Jane Tyska/Bay Area News Group via AP)

In Seattle, a group of about 100 protesters gathered in the Capital Hill neighborhood, blocked roads and set a trash bin on fire.

The Oakland protest grew to about 250 people by late Tuesday evening, according to police. Officer Marco Marquez said protesters damaged five businesses, breaking windows and spraying graffiti.

Police issued a citation for a vehicle code violation, but did not make any arrests.

A woman was struck by a car and severely injured when protesters got onto a highway early Wednesday morning, the California Highway Patrol said. Protesters vandalized the driver’s SUV before officers intervened. The highway was closed for about 20 minutes.

Marquez said the department is fully staffed for the possibility of another protest Wednesday evening.

Oakland is a hotbed of violent protest in the San Francisco Bay Area. Protesters briefly shut down two major freeways, vandalized police cars and looted businesses two years ago when a Missouri grand jury decided not to indict a white police officer in the fatal shooting of a black teenager in Ferguson.

And nearly 80 people were arrested after a night in 2010 that saw rioters using metal bats to break store windows, setting fires and looting after a white transit police officer, Johannes Mehserle, was acquitted of murder and convicted of involuntary manslaughter in the slaying of Oscar Grant, an unarmed black man who was shot dead on a train platform the previous year.

Elsewhere in California, more than 1,000 students at Berkeley High School staged a walk-out and marched to the campus of UC Berkeley.

Police said at least 500 people swarmed on streets in and around UCLA, some shouting anti-Trump expletives and others chanting “Not my president!”

Smaller demonstrators were held at University of California campuses and neighborhoods in Irvine and Davis and at San Jose State.

This is a developing story. Stay with 8News online and on air for the latest updates.